Back digging shovel



Original Filed July 27, 1928 Jafidl 2. ya,

\INVENTOR. BYXMfWX A TTORNEYS.

Patented Nov. 3, 1931 UNITED STATES PATENT v OFFICE MITCHELL L. FYKSE,OF SOUTH MILWAUKEE, .WISCONSIN, ASSIGNORTO BUCYBUS-ERIE COMPANY, OFSOUTH MILWAUKEE, WISCONSIN, A CORPORATION OF DELAWARE BACK DIGGINGSHOVEL Original application filed July 27, 1928, Serial No. 295,661.Divided. and this application filed May 13, 1929. Serial No. 362,627.

My invention relates to new and useful improvements in back diggingshovels.

This application is a divisional of my copending application, Serial No.295,661, filed 5 July 27, 1928.

Back digging shove-ls are well known in the excavating art. They arecharacterized by a dipper mounted on the lower end of a handie, which ispivoted intermediate its ends on 10 the outer end of the boom, the innerend of the boom being pivoted to the frame of the machine. The shovelfaces toward the machine. On' the main frame of the machine is atwo-drum winch, from which one rope,

" associated with the dipper, tends to drag the dipper toward themachine. The other rope of the winch is associated with the upper end ofthe dipper handle and tends both to raise the boom and to cause thedipper to move away from the machine.

The principal object of my invention is to provide novel locking meansso that the two ropes will not waste power pulling against 7 1 eachother during the hoisting of the boom.

J Further objects and advantages of my invention will be readilyevident, as the descrip tion progresses.

The invention consists in the novel parts,

and in the combinations and arrangements 40 of a power shovel embodyingmy invention.

Referring to the drawing, it will be seen that 5 is the main base of thepower shovel, supporting the boom 6, the A-frame 7 and the main winch 8.The main winch 8 includes two hoist drums 9 and 10, aotuable by anyconvenient power source (not shown).

On the outer end of boom 6 is a hinge pin 11, which serves as ahorizontal pivot for the handle 12. Hinged to the boom by the hinge pin11 is a swivel piece 13 provided with a swivel axle 1 1 which extendsthrough a hushed hole in the handle 12.

A spring bumper 26 is provided on the top of the outer end of the boom'6 to contact with bumper plate 27 of the handle 12 whenever the handleis in its most extended position.

On the upper end of the handle are two hoist sheaves 28, and on abracket 29 in the lower end of the handle is a padlock sheave 30.

A digging dipper 31 is held by the lower end of the handle 12 and by abrace 32.

A rope 37 passes from an anchorage 34 on the'boom 6, around the padlocksheave 30, thence through the boom and between two guide sheaves 38 onthe A-frame 7, to the drum 9 of the main winch 8. A rope 39 is anchoredin a rope socket 40 which is pivoted to the apex of the A-frame 7 Thisrope then passes around one of the hoist sheaves 28, thence around oneof the sheaves 11 at the apex of the A-frame, thence around the otherhoist sheave 28, thence around the other sheave 41 at the apex of theA-frame, and thence to the drum 10 of the main winch 8.

Digging is accomplished by pulling in on rope 37, the exact height ofdigging being varied by slightly pulling in or paying out rope 39. henthe full dipper 31 has been pulled as near as possible to the boom 6, itis maintained in that position by further pulling in on the rope 37, ashoisting is accomplished by rope 39. When hoisted to the desired spot,dumping is effected by pulling in on rope 89 and simultaneously payingout rope 87.

It will be noted that during the hoisting operation, it is necessarythat the two ropes should pull against each other, at considerable wasteof winchenergy. Accordingly there are provided two hooks 42 dependingfrom the outer end of the boom 6, and a cooperating bar 43 extendingthrough the handle 12 and beyond its sides. When the dipper is drawntoward the machine in digging, the bar 43 engages the hook 42automatically. Then, in hoisting, power need be applied only to the rope39. hen hoisting has been accomplished, the hooks 42 are then in such aposition that they would tend of their own weight to fall away fromcontact with the bar a3, were it not for the fact that this bar ispulling against the curved part of the hooks and thus holds them inposition. However, the moment that, in this position, a slight pull isgiven to rope 37, the hooks are disengaged and fall away from the bartoward the boom, so that a subsequent pull on rope 39 will cause thedipper to swing away from the machine to dump.

Having now described and illustrated one form of my invention, I wish itto be understood that my invention is not to be limited to the specificform or arrangement of parts hereinbefore described, except in so far assuch limitations are specified in the appended claims.

I claim:

1. In a machine of the class described, the combination of: a mainframe; a boom, pivoted at its lower end to the frame, for swinging in avertical plane about its pivot; a dipper handle, pivoted intermediateits ends at the outer end of the boom; a digging dipper; a hoisting ropeassociated with the upper end of the handle; a digging rope associatedwith the lower end of the handle; a catch-member on the boom; and acatchmember on the handle, to engage the catchmember on the boom underthe influence of the digging rope when the boom is at a rela tivelysmall angle with the horizontal, and to disengage under the influence ofthe digging rope when the boom is at a relatively large angle with thehorizontal.

2. In a machine of the class described, the combination of: a mainframe; a boom, pivoted at its lower end to the frame, for swinging in avertical plane about its pivot; a dipper handle, pivoted intermediateits ends at the outer end of the boom; a digging dipper; a hoisting ropeassociated with the upper end of the handle; a digging rope asso ciatedwith the lower end of the handle; and means for locking the handle,against swing-- ing with respect to the boom, during hoisting, wherebyto prevent the two ropes from pulling against each other; said meansautomatically engageable during digging, and being adapted to disengageby a pull on the digging rope after hoisting.

3. In a machine of the class described, the combination of: a mainframe; a boom, pivoted at its lower end to the frame, for swinging in avertical plane about its pivot; a dipper handle, pivoted intermediateits ends at the outer end ofthe boom; a digging dipper; a hoisting ropeassociated with the upper end of the handle; a digging rope associatedwith the lower end of the handle; a hook on the boom; and a bar on thehandle, to engage the hook under the influence of the digging rope whenthe boom is at a relatively small angle with the horizontal, and todisengage under the influence of the digging rope when the boom is at arelatively large angle with the horizontal.

In testimony whereof I aflix my signature.

MITCHELL L. FYKSE.

